Power laws in microrheology experiments on living cells: Comparative analysis and modeling.

We compare and synthesize the results of two microrheological experiments on the cytoskeleton of single cells. In the first one, the creep function J(t) of a cell stretched between two glass plates is measured after applying a constant force step. In the second one, a microbead specifically bound to transmembrane receptors is driven by an oscillating optical trap, and the viscoelastic coefficient Ge(omega) is retrieved.

Rotational magnetic particles microrheology: the Maxwellian case.

An experimental method based on the rotational dynamics of a magnetic probe is reported to measure the local viscoelasticity of soft materials on microscopic scales. The technique is based on the alignment of dipolar chains of submicrometer magnetic particles in the direction of an applied magnetic field. On one hand, light scattering is used to detect the chains' oscillations over a 0.

Local rheological probes for complex fluids: application to Laponite suspensions.

We present an experimental method allowing a direct measurement of the local rheological behavior of complex fluids. A magnetic probe is inserted into the bulk of the fluid and submitted to a controlled magnetic force or torque, which induces a mechanical perturbation of the fluid. The geometry of the perturbation can be varied using two kinds of probes: a magnetic bead submitted to a homogeneous magnetic force in one direction, and a magnetic needle that can turn inside the material under the effect of an applied magnetic torque.

Nucleotide sequence analysis of four genes, hupC, hupD, hupF and hupG, downstream of the hydrogenase structural genes in Bradyrhizobium japonicum.

The nucleotide sequence of a 2.2 kb region downstream of the hydrogenase structural genes in Bradyrhizobium japonicum was determined. Four genes encoding predicted polypeptides of 27.

[Benigne multi-recurrent meningitis (Mollaret's disease). A case in a child of 2 years and 8 months].

The authors report a case of meningitis, presenting all characteristics of the disease described in 1944 by P. Mollaret, occurring in a child aged 2 years and 8 months. They stress the rarity of cases on childhood.